Recent developments and improvements in relation to fluorescent lighting tubes and also improvements in the so-called "ballasts" utilised to power such tubes, have provided for dramatic savings in the power consumption of such tubes. In the past, such tubes were typically of a diameter of about 1 and 1/2 inches, and were either provided with a single connection pin at each end or two connection pins. The tubes were also provided in various lengths, such as two foot, three foot, four foot, five foot, six foot lengths and also eight foot lengths.
Tubes in different lengths have been provided, but the most common lengths in use are four foot tubes and eight foot tubes.
Another factor in the use of such tubes is that whereas tubes of four foot or less commonly are provided with two electrical connection pins at each end, longer tubes such as eight foot tubes are commonly provided (with some rare exceptions in high power tubes) with only a single pin at each end. As a result, the electrical lamp sockets into which shorter tubes are fitted, provide two electrical contacts, to contact the two pins at each end. On the other hand the electrical lamp sockets into which the eight foot tubes are connected are provided with only a single contact at each end to contact the single pin.
New improved technology tubes having a reduced power consumption are presently available economically as two, three, and four foot tubes, having two pins at each end. Eight foot high efficiency tubes are now becoming available, but are not economical. They require two men for installation, and a costly new ballast. In the case of many office and commercial institutions, it is a relatively simple matter to simply remove the existing shorter tubes and replace them with the improved technology tubes assuming they are the same length. However, in the case of many industrial and commercial applications, longer tubes, particularly eight foot tubes are the standard. As yet, the new technology tubes have not been economically available in excess of four feet, and have not been provided in the "single pin" configuration.
In addition new higher efficiency ballasts are available which further reduce power consumption.
As a result, as at the present time, it is not possible to use the new high technology low-power consumption shorter tubes in other than existing fixtures of the same lengths.
Clearly, it is highly desirable to provide a system whereby the new high technology shorter tubes (i.e. four feet or less), and also the new high technology low power consumption ballasts, can be used in commercial and industrial situations, which are presently using longer old technology tubes of five feet or more. Obviously, this could readily be done by simply discarding the longer, i.e. eight foot tube lighting fixtures, and replacing them with twice the number of four foot tube, lighting fixtures.
However, the cost of doing this would be very substantial. The savings in power consumption would be offset by the very considerable increase in capital costs. Consequently, this simple obvious solution has not proved attractive.
Another solution is to remove the existing ballast cover plate and replace it with a new one, having openings to receive the high technology lighting receptacles. This is however a substantial expense, and requires specially designed new ballast cover plates to match various different makes of electrical fixtures. In some designs the ballast cover plate is not removeable, but is part of the box. In this case the whole fixture would have to be replaced.
Preferably, it would be desirable to provide a retrofitting apparatus which can be attached directly to the ballast cover plate of the old technology longer tube lighting fixture, adapting it to a receive two, or four or more, high technology tubes, in place of the single or multi old technology tubes presently in use, and also which permits a simple system for replacing the old ballast with the new high technology ballast.